Reuleaux Triangle Disks: New Shape on the Block

We report here the unprecedented preparation of Reuleaux triangle disks. The hydrolysis and precipitation of bismuth nitrate in an ethanol–water system with 2,3-bis­(2-pyridyl)­pyrazine yielded basic bismuth nitrate Reuleaux triangle disks. Analysis of the intermediates provided insights into the mystery behind the formation of the Reuleaux triangle disk, revealing a unique growth process. The report of a facile method to prepare crystals of a novel shape in high yield, with good homogeneity, and with excellent reproducibility is expected to unlock new research directions in multiple disciplines

[Cp*IrCl₂]₂ Catalyzed Formation of 2,2′-Biindoles from 2‑Ethynylanilines

[Cp*IrCl₂]₂ catalyzes the cyclization of 2-ethynylanilines to 2,2′-biindoles via intramolecular hydroamination. A reaction pathway has been proposed on the basis of deuterium labeling experiments and computational studies

A Robust Pentacoordinated Iron(II) Proton Reduction Catalyst Stabilized by a Tripodal Phosphine

A pentacoordinated triphosphine benzenedithiolatoiron­(II) complex containing a vacant site for binding has been prepared and characterized. The complex is found to be a robust proton reduction catalyst with an overpotential of 0.56 V and a turnover frequency of 2900 s^–1 with respect to 0.28 M acetic acid as the proton source. A mechanism describing the electroproton reduction process has been proposed

Intramolecular C–C Bond Coupling of Nitriles to a Diimine Ligand in Group 7 Metal Tricarbonyl Complexes

Dissolution of M­(CO)₃(Br)­(L^Ar) [L^Ar = (2,6-Cl₂-C₆H₃-NCMe)₂CH₂] in either acetonitrile [M = Mn, Re] or benzonitrile (M = Re) results in C–C coupling of the nitrile to the diimine ligand. When reacted with acetonitrile, the intermediate adduct [M­(CO)₃­(NCCH₃)­(L^Ar)]Br forms and undergoes an intramolecular C–C coupling reaction between the nitrile carbon and the methylene carbon of the β-diimine ligand

Solubilizing Metal–Organic Frameworks for an <i>In Situ</i> IR-SEC Study of a CO₂ Reduction Catalyst

Metal–organic frameworks (MOFs) are typically assembled by bridging metal centers with organic linkers for various applications, including providing robust support for heterogeneous catalysts for CO2 reduction. In this study, we have demonstrated the solubilization of a MOF tethered to a CO2-reducing electrocatalyst and studied its fundamental electrochemistry in THF solvent using infrared spectroelectrochemistry (IR-SEC). The fundamental electrochemical properties of this immobilized catalyst were compared to that of its homogeneous counterpart. This approach provides a foundation for future experimental studies to bridge the gap between homogeneous and heterogeneous electrocatalysis

The Dithiolate-Bridged Diiron Hexacarbonyl Complex Na₂[(μ-SCH₂CH₂COO)Fe(CO)₃]₂ as a Water-Soluble PhotoCORM

The water-soluble dimercaptopropanoate-bridged diiron hexacarbonyl complex Na₂[(μ-SCH₂CH₂COO)­Fe­(CO)₃]₂ has been prepared, and the X-ray crystal structure and infrared, UV–visible, and ESI spectra of the complex have been obtained. The complex is shown to behave as a photoCORM, whereby all six CO ligands are released within 30 min of visible-light irradiation. Gas-phase FTIR spectroscopy has been used to quantify the release of CO into the headspace above the aqueous solution. The resulting product, tentatively assigned to an iron thiolate salt, is also water-soluble. Cell viability studies show that Na₂[(μ-SCH₂CH₂COO)­Fe­(CO)₃]₂ is not cytotoxic toward normal epithelial cells

Photochemical Reaction of Cp*Ir(CO)₂ with C₆F₅X (X = CN, F): Formation of Diiridium(II) Complexes

Visible light irradiation of Cp*Ir­(CO)₂ (<b>1</b>) in pentafluorobenzontrile resulted in the formation of the two isomeric diiridium­(II) complexes [Cp*Ir­(μ-CO)­(C₆F₄CN)]₂ (<b>3</b>) and [Cp*Ir­(CO)­(C₆F₄CN)]₂ (<b>4</b>), while the analogous reaction of <b>1</b> in hexafluorobenzene to give [Cp*Ir­(μ-CO)­(C₆F₅)]₂ (<b>3a</b>) required UV irradiation. Complex <b>4</b> isomerizes to <b>3</b> under visible light irradiation. A reaction pathway to <b>4</b> involving aromatic nucleophilic substitution has been proposed on the basis of experimental and computational data. The isomerization of <b>4</b> to <b>3</b> is believed to proceed via a radical species resulting from homolytic fission of the Ir–Ir bond

Photochemical Reaction of Cp*Ir(CO)₂ with C₆F₅X (X = CN, F): Formation of Diiridium(II) Complexes

Visible light irradiation of Cp*Ir­(CO)₂ (<b>1</b>) in pentafluorobenzontrile resulted in the formation of the two isomeric diiridium­(II) complexes [Cp*Ir­(μ-CO)­(C₆F₄CN)]₂ (<b>3</b>) and [Cp*Ir­(CO)­(C₆F₄CN)]₂ (<b>4</b>), while the analogous reaction of <b>1</b> in hexafluorobenzene to give [Cp*Ir­(μ-CO)­(C₆F₅)]₂ (<b>3a</b>) required UV irradiation. Complex <b>4</b> isomerizes to <b>3</b> under visible light irradiation. A reaction pathway to <b>4</b> involving aromatic nucleophilic substitution has been proposed on the basis of experimental and computational data. The isomerization of <b>4</b> to <b>3</b> is believed to proceed via a radical species resulting from homolytic fission of the Ir–Ir bond

Significant O–H Bond Weakening in CpMn(CO)₂(CH₃OH): Evidence for the Generation of the CpMn(CO)₂(CH₃O) Radical upon H Atom Abstraction by O₂

The UV–visible photolysis of CpMn­(CO)₃ in methanol generates CpMn­(CO)₂(CH₃OH), which upon H atom abstraction using either O₂, dpph, or H₂O₂ gives the CpMn­(CO)₂(CH₃O) radical complex. The radical with a lifetime of 10 to 20 min has been mainly characterized using FTIR and ESR spectroscopy and chemical oxidation studies. Together with density functional theory calculations, it is shown that the O–H bond is significantly weakened in the CpMn­(CO)₂(CH₃OH) complex compared to free methanol. NBO spin density analysis suggests that the bond cleavage is facilitated by the formation of the CpMn­(CO)₂(CH₃O) radical in which the electron spin is localized at the metal center rather than at the oxygen atom

The Dithiolate-Bridged Diiron Hexacarbonyl Complex Na₂[(μ-SCH₂CH₂COO)Fe(CO)₃]₂ as a Water-Soluble PhotoCORM

The water-soluble dimercaptopropanoate-bridged diiron hexacarbonyl complex Na₂[(μ-SCH₂CH₂COO)­Fe­(CO)₃]₂ has been prepared, and the X-ray crystal structure and infrared, UV–visible, and ESI spectra of the complex have been obtained. The complex is shown to behave as a photoCORM, whereby all six CO ligands are released within 30 min of visible-light irradiation. Gas-phase FTIR spectroscopy has been used to quantify the release of CO into the headspace above the aqueous solution. The resulting product, tentatively assigned to an iron thiolate salt, is also water-soluble. Cell viability studies show that Na₂[(μ-SCH₂CH₂COO)­Fe­(CO)₃]₂ is not cytotoxic toward normal epithelial cells